Toaster-coated unit



April 13, 1943. J. w. MYERS 2,316,699

TOASTER-COATED UNIT Filed May 24. 1940 Patented Apr. 13, 1943 UNITED STATES PATENT OFFICE TOASTEBCOATED 'UNIT Application May 24, 1940, serial No. 33u53 (ci.v 21a-1s) 3 Claims.

setoir electrical heating-elements arranged alongrespectively opposite sides of leach such well, the cconomicalgand manuiacturingadvantages to be gained by: the use offaelngle on common heating unit' tbetwo-fhread wells of a toaster otr the present type. are well recognized, and some manuiacmrers'offtoastersihave resorted to the use oi' a common intermediate'heating unit in order toireduce the cost o! manufacturing such toastcrsand, consequently, the sales price thereof totnepnnlle. M f

Howevera intheseatoasters which employ a' common intermediate heating unit, an unbal, ancd operating conditionoccurs and manifests itselil` particularly 'in instances when a slice of bread isffbeing'rtoasted. in 'only one of thetwo wells. This unbalanced operation results in an uneven sriace cooking or toasting vof the oppositesidesoithesliccof bread fand the inner surfac'ewill very-'often beburntbeiore the ontsurfcefis' toasted to. the desired degree."v Intastezs 'oiftns typenereinvolved which-'em'- vploy a separate set of heating elements for 'each of thebread wells, such unbalanced operation;- if

presenhtoappreciable extent; may ber'eadiv Yy eliminatai by providingadequate' heat `insu1a' tionlbet'we'e'the'inne heating elements. :It ls'- bbvioslirlmpossibie; however, -to thuseuml; nate' -te'mblanced condition in toasters' emaicnlmn intermediate heating. element and prioritoastera bf'this'type have' been unsatisl tactoryibeeuseioti this condition't "It has been generally believed-thatthefunbaianced operation occurring-'fin suoli toasters is due totra'nsie'r of heattomffthe'idle heating` element` through the nnus'ed'vveli; cansingtlie-"degree oi beati adjacent tiieinnc'srfac ol a single slice ofi bread tc'be materiallyrgreateiv than that generated adjacent the outer' surfac'ethereof. l"Accordingy, and in view of the impossibility oi employing heat iusulation, it has seemingly been impossible to obviatethis-conditlon." Y

However', I'havenisdovered that this unbezanced'operation in toasters employing a single intermediate heatingelement is caused particularlyfbythe'intermediate heatlng'unit acting as au absorber and re-radiator of heat; I have de# termined that this unit rta-radiates toward the bread slice the excessive heat absorbed from the idle heatingelement. *The combined eiect of such 4heat absorption and re-radiation by the intermediate unit is to subject the inner surface of the bread slice to excessive temperature. thus causing opposite sides thereof to be unevenly toasted.' .1' With the foregoing in, mind, the principal ob ject of Athe'present inventionis to provide an electrical heatingjunit Iwhich can be employed satisfactorily-between the 4-breadfwells o! a twoslice toaster as a common heating. means ther-ef for and which is Aconstructed 'and arranged .at all times to provide balanced operation and uniform toasting of the opposite sideslof a slice of bread. 'y x.: .if

Anotherobject o! the invention ils-ttt` provide an electrical heating unit` oithe character set forth embodying certainnovelieatures of construction and arrangement Ywhereby the radiating action of such unit is so controlled that the heat given oi by the opposite sides of said unit is sub,- stantlally balanced in relationj-to the'heat generated by the outer heating units independently of the presence or absence oi bread=slices. c

These and'otherobiects of the invention and the various features and details of the constructin',1 arrangement and operation fthereoi.. are hereinafter'. 4fullyi set yforth and describedand shown in`the1accompanying drawing, in which:

Fig-ure' 1 is-a;sectiona11.perspectlve view oi a two-slice'toaster having, interposed-between the adjacent wells thereofV an electricalA heating unit made .according to the present invention.

-Figure 2is al view in elevationoiairelectrical heating-unit made according to ,this invention;

md l Ir i. *""131 'i r :"'YQfi- Figure 3isran `enlargedtIragnlentai'y'vilevil in section verticallythrough a,- portioniot the heat-` ingunit-illustrated-in-Figure :2m

' A- physical' embodiment oi.- a toaster, of the type here involved employinganhelectrlcal heating unitV according tothelpresent invention is ,shown infFiguregi rofthedrawingfandvreierring to this ligure; there is illustrated-a toaster of the twof siicetype-comprisingsa body i; having recesses or-'wells 2-and 3 adaptedto receive Athe bread Slicsglas W81) understood.

Inthis particular type of toaster thebread slices are supported by carriages 4 which move vertically within-the wells upon guides 5. This general construction of the particular toaster illustrated and the means and mechanism (not shown) for lowering and raising the carriages 4 are conventional and form no part of the invention. It is, therefore, unnecessary to discuss such structure in further detail.

Within the bread wells 2 and 3 there are provided the usual electrical heating elements E and 'I disposed adjacent the side walls of the body I of the toaster and arranged to surface cook or toast the outer surfaces of bread slices inserted in the said wells. Intermediate the wells 2 and Il there is provided a single electrical heating unit B which is adapted to surface cook or toast the adjacent inner surface of bread slices in both of said wells, and it is to this intermediate heating unit 8 that the present invention is particularly directed.

Referring now to Figure 2 of the drawing, the electrical heating unit 8 includes the usual supporting or body structure 9 which, in the form illustrated, consists of two identical sheet mica sections I suitably secured together by a clamp Ii in contiguous laterally adjacent relation, and on these respective sections Ill of said body structure there are wound portions of a continuous length of at resistance wire I2, the opposite ends of which are connected to electrical connectors I3.

Electrical heating units of generally similar construction have been used heretofore in toasters, but when employed as a common heating means intermediate the adjacent bread Weils of a two-slice toaster they have proved highly objectionable due to the unbalanced operating condition and uneven toasting which occurs particularly when only one bread well of the device is used.

Now as hereinbefore stated, I have discovered that this unbalanced operation is caused by undesired absorption and re-radiation of heat by the intermediate heating unit, and, therefore, the particular feature of the present invention resides in the novel manner and means whereby such undesired heat absorption and re-radiation is effectively prevented so as to produce a balanced heat condition in the two bread wellls of the toaster irrespective of whether one or both of the Wells is being used.

According to the present invention, the undesired absorption and re-radiation of heat by the said heating unit is effectively prevented by so constructing the unit that its heating effect is due substantially entirely to the heat generated in its resistance wire by the passage of current therethrough. This result may be attained conveniently and economically by coating the surfaces of the body structure 9 of said unit over which lie the respective portions of the resistance wire I2 with a suitable non-radiating material such as best shown in Figures 2 and 3 of the drawing. The coating must be capable of withstanding high ternperatures and especially must not be such as would tend to short-circuit the adjacent spans of the resistance wire I2 which overlies such coating.

These characteristics and properties desired for the coating I 4 are each present in aluminum paint and its use as such a coating is, therefore, preferred. Furthermore, in addition to providlng excellent protection against heat re-radlation therefrom, I nd that aluminum paint provides a coating having a surface which not only has these properties but which tends also to reflect back any heat radiating against such surface, and the effectiveness of the coating is thereby materially increased.

Too, aluminum paint is fully capable of withstanding high degrees of temperature and while metallic aluminum is generally acknowledged to be a conductor of electricity, the paint vehicle carrying the aluminum is such as to effectively prevent the coating from causing a short-circuit between adjacent spans of the overlying resistance wire I2. The paint vehicle imparts to the coating a high electrical resistance, or in other words, causes the paint to be substantially nonconducting. It is important, however, that some of the vehicle residue remains intact and it does not all burn out under the influence of high temperatures. Preferably, the coating i4 is not extended to the edges of the unit but terminates a slight distance from each edge, as shown in Figure 2. This further minimizes the possibility of current leakage through the coating, since the coating does not come into contact with the resistance wire along the vertical edge portions where the support 9 is rmly engaged by the wire.

The aluminum paint coating I4, of course, is applied to the sheet mica body 5 of the heating unit before the resistance wire I2 is wound thereon and may be applied in any suitable manner, for example, by spraying or by printing it from rubber plates.

It is essential that both sides of the unit be coated as above described in order to prevent the unbalanced operation of the toaster. As explained above, the unit tends to act as an absorber and re-radiator of heat and thisV undesired action can only be prevented effectively by coating both sides. This renders the unit substantially incapable of radiating heat other than that generated in its heating element.

From the foregoing it will be seen that the present invention provides an improved toaster employing a common heating unit between the bread wells novelly constructed to provide at all-times a balanced heat condition within each bread well of the toaster, insuring uniform surface cooking or toasting of both sides oi' the bread slices whether both or only one of said bread wells is used.

While a particular embodiment of the invention has been herein illustrated and describedit is not intended that the invention be limited to such disclosure but that changes and modications may be incorporated and made therein within the scope of the annexed claims.

I claim:

l. In a bread toaster, a pair of adjacent bread wells adapted to receive bread slices to be toasted, a pair of outer electrical heating units disposed respectively at the outer sides o1' said wells for toasting the outer surfaces of said bread slices, and an intermediate electrical heating unit between said wells for toasting the inner surfaces of said bread slices, said intermediate unit comprising an insulating supporting sheet, a coating of aluminum paint on each of the opposite faces of said sheet, and resistance wire wound about said sheet and disposed adjacent the coated faces thereof, said coating serving to thermally isolate said wells from one another without deleteriously affecting the insulating character of the surfaces of said sheet.

2. In a bread toaster, a pair of adjacent bread wells adapted to receive bread slices to be toasted. a pair of outer electrical heating units disposed respectively at the outer sides of said wells for toasting the outer surfaces of said bread slices, and an intermediate electrical heating unit between said wells for toasting the inner surfaces aslacae of said bread slices, said intermediate unit comprising an insulating supporting sheet, a coating of aluminum paint on each of the opposite faces of said sheet, said coating terminating a slight distance from the edges of said sheet where the resistance wire rmly engages the supporting sheet, and resistance wire wound about said sheet and disposed adjacent the coated faces thereof, said coating serving to thermally isolate said wells from one another without deleteriously ailecting the insulating character of the surfaces of said sheet.

3. In a bread toaster, a bread well adapted to receive a bread slice to be toasted, an electrical heating unit disposed at one side of said well for toasting one surface of the bread slice, and an electrical heating unit disposed at the opposite side of said Well for toasting the other surface of the bread slice, said last-named unit comprising an insulating supporting sheet, a coating of aluminum paint on the face of said sheet adjacent the inserted bread slice, and resistance wire supported on said sheet adjacent the coated face thereof, said coating serving to thermally isolate said Well from the opposite side of said sheet without deleteriously affecting the insulating character of the surface of said sheet.

JOSEPH W. MYERS. 

